JP2009039265A - Non-invasive biological information measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a noninvasive living body information measuring apparatus for estimating a feature amount with low power consumption.
SOLUTION: A light source 210, a control means 300 for controlling activation of the light source 210 or each means described later, an N-channel biological information sensor 220 for measuring biological information, and an output signal of the biological information sensor 220 are amplified, A storage means 250 for A / D converting the amplified signal and storing the converted digital data, and a series of operations until the light source 210 is turned on and the digital data is recorded in the storage means 250 are repeatedly stored X times. And a feature amount estimation means 260 for averaging the digital data stored in 250 and analyzing the averaged M channel (M <N) data to estimate the feature amount of the biological information. The M channel is determined in advance at the time of repeating (Y <X) times, and the operation after the amplification means of the channel not used for feature amount estimation is performed until X times thereafter. By stopping the operation, low power consumption can be realized.
[Selection] Figure 2

Description

  The present invention relates to a biological information detection apparatus that measures biological information and monitors the state of the biological body.

  The number of patients with diabetes, a typical lifestyle-related disease, is increasing worldwide. Diabetic patients require routine glycemic control to reduce complications from diabetes and improve the quality of life of patients. Therefore, patients must measure blood glucose regularly every day under the guidance of a doctor. As a typical method for measuring a blood glucose level, there is an invasive blood glucose measuring device that measures blood glucose level by collecting blood by inserting a patient's finger. A noninvasive blood glucose measurement device that does not require blood collection has been proposed because it involves labor and pain when blood is collected by puncturing a finger and there is a risk of infection and the like.

  As a non-invasive blood glucose measurement device, a “biological measurement system” using a photoacoustic effect is described. Light of a wavelength absorbed by glucose is irradiated from a biological measurement system onto a part of a living body such as a fingertip, and the irradiated light is collected at a relatively small focal region in the living body, and is generally light. Is absorbed by glucose and converted to kinetic energy in the tissue in the region adjacent to the focal region. Kinetic energy increases the temperature and pressure of the absorbing tissue region and generates sound waves. This sound wave is hereinafter referred to as “photoacoustic wave signal”. The photoacoustic wave signal is emitted from the absorbing tissue region and detected by an acoustic sensor included in the biological measurement system. The acoustic sensor is mounted in contact with the living body surface. The intensity of the photoacoustic wave signal is a function of glucose in the absorbing tissue region, and the intensity measured by the sensor is used to examine the blood glucose level. At this time, in order to minimize the influence of noise in one measurement, the blood glucose level is measured by averaging a series of measurement results (for example, Patent Document 1).

Further, “non-invasive biological information measuring method and biological information measuring device” is described as another non-invasive blood glucose measuring device using the photoacoustic effect. In this method, photoacoustic wave signals generated by light irradiated on a living body are detected by a plurality of acoustic sensors, and after a plurality of detected signals are amplified, necessary signals are selected to measure a blood glucose level. The detection efficiency can be maximized by selecting an acoustic sensor that minimizes the distance between the source of the photoacoustic wave signal and the acoustic sensor (for example, Patent Document 2).
Special table 2001-526557 gazette JP 2004-147940 A

  However, in the techniques described in Patent Document 1 and Patent Document 2, in order to minimize the effects of noise and body movement, the measurement is performed a plurality of times and an operation of averaging a series of measurement results is performed. In order to perform each acoustic sensor, it is necessary to provide a plurality of electric circuits for signal amplification and A / D conversion. Therefore, it has a problem that it requires a large amount of power consumption and is not suitable as a portable product.

  The present invention has been made to solve the conventional problems, and an object of the present invention is to provide a noninvasive living body information measuring apparatus capable of realizing low power consumption.

  In order to solve the above-described conventional problems, a noninvasive living body information measuring apparatus according to the present invention includes at least one light source, a control unit that controls lighting timing of the light source and activation of each unit described below, and biological information. A biological information sensor of N channels (N is a natural number of 2 or more) measured for a predetermined time, amplification means for amplifying an N channel output signal obtained from the biological information sensor, and the amplified N channel amplified signal A A / D conversion means for / D conversion, first storage means for storing the A / D converted N-channel digital data, and turning on the light source and recording the digital data in the first storage means The above-described series of operations are repeated X times (X is a natural number of 2 or more), and the averaging means for averaging the digital data stored in the first storage means, and the averaging Data selection means for selecting averaged data of M channels (M is a natural number equal to or less than N) to be used in a feature amount estimation means to be described later, and biological information from the averaged data selected by the selection means In the non-invasive living body information measuring apparatus provided with the feature quantity estimation means for estimating the feature quantity, when the series of operations is repeated Y times (Y is a natural number less than X), the averaging means and the signal selection means Thus, the channel to be used by the feature quantity estimation means is determined in advance, and the operation after the amplification means for the channel not used by the feature quantity estimation means is stopped until X times thereafter.

  Further, in the non-invasive living body information measuring apparatus, the signal selection means compares the averaged amplitude peak level of the digital data for N channels, and selects an adjacent M channel including a channel having the maximum amplitude peak level. It is characterized by that.

  Furthermore, in the non-invasive living body information measuring apparatus, the signal selection means compares N timings of sampling timings at which the amplitude peaks of the averaged digital data are generated, and includes an adjacent channel including a channel having the earliest amplitude peak generation timing. The M channel to be selected is selected.

  Furthermore, in the non-invasive living body information measuring apparatus, the signal selection means includes a first writable register, and the light source is turned on by the first register until digital data is recorded in the first storage means. It is possible to change the X number of times of a series of operations from the outside.

  Further, in the non-invasive living body information measuring apparatus, the signal selecting means includes a writable second register, and the operation stop timing after the amplifying means of the channel not used in the feature amount estimating means by the second register. It is possible to change the Y times indicating the value from the outside.

  The noninvasive living body information measuring apparatus according to the present invention includes at least one light source, a control means for controlling lighting timing of the light source and activation of each means described later, and an N channel (N Is a natural number of 2 or more), amplification means for amplifying an N-channel output signal obtained from the biological information sensor, and A / D conversion for A / D conversion of the amplified N-channel amplification signal A first storage means for storing the A / D-converted N-channel digital data, and a series of operations until the light source is turned on and the digital data is recorded in the first storage means X times (X is a natural number of 2 or more) Averaging means for repeatedly averaging digital data stored in the first storage means, and a special feature described later by analyzing the averaged data. Signal selection means for selecting average data of M channels (M is a natural number equal to or less than N) used by the quantity estimation means, and feature quantity estimation for estimating the feature quantity of biological information from the averaged data selected by the selection means In the non-invasive living body information measuring apparatus provided with the means, at the start of the series of operations, the operation after the amplification means is performed in the Z channel (Z is a natural number less than N), and the series of operations is performed Y times (Y is greater than X). (Small natural number) At the time of repetition, N-channel data is created by interpolating the Z-channel data input in the averaging means, and the feature-value estimating means uses the N-channel data in the signal selection means. The channel to be used is determined in advance, and the operation after the amplifying unit of the channel not used by the feature amount estimating unit is performed up to X times thereafter. It is characterized in that stop.

  Further, in the non-invasive living body information measuring apparatus, the signal selection means compares the averaged amplitude peak level of the digital data for N channels, and selects an adjacent M channel including a channel having the maximum amplitude peak level. It is characterized by that.

  Furthermore, in the non-invasive living body information measuring apparatus, the signal selection means compares N timings of sampling timings at which the amplitude peaks of the averaged digital data are generated, and includes an adjacent channel including a channel having the earliest amplitude peak generation timing. The M channel to be selected is selected.

  Furthermore, in the non-invasive living body information measuring apparatus, the signal selection unit includes a third writable register until the light source is turned on by the third register and digital data is recorded in the first storage unit. It is possible to change the X number of times of a series of operations from the outside.

  Further, in the non-invasive living body information measuring apparatus, the signal selecting means includes a writable fourth register, and the operation stop timing after the amplifying means of the channel not used by the feature amount estimating means by the fourth register. It is possible to change the Y times indicating the value from the outside.

  Furthermore, in the non-invasive living body information measuring apparatus, the signal selection means includes a fifth writable register, and the fifth register operates after the amplification means at the start of the series of operations in all N channels. It is possible to change the Z channel indicating the channel for performing the operation from the outside.

  According to the noninvasive living body information measuring device of the present invention, a device with low power consumption can be realized.

  Embodiments of the noninvasive living body information measuring apparatus of the present invention will be described below in detail with reference to the drawings.

(Embodiment 1)
In Embodiment 1 of the present invention, the noninvasive living body information measuring device assumes a noninvasive blood glucose measuring device 100 using a photoacoustic method.

  FIG. 1 is a diagram showing a system configuration including a non-invasive blood glucose measurement device 100 according to Embodiment 1 of the present invention. In FIG. 1, 100 is a non-invasive blood glucose measuring device, 111 is light, 120 is a living body, 130 is a blood vessel, and 131 is a photoacoustic wave signal. (A) is an activation signal 302, (b) is a lighting timing 301, (c) is a photoacoustic wave signal 131, (d) is an end signal 303, and (e) is an estimated blood glucose level output timing. In the repeated measurement, a series of operations are performed for each measurement cycle, with one measurement interval as the measurement unit and the interval until the blood sugar level is estimated as the measurement basic cycle.

  The noninvasive blood glucose measurement device 100 according to the first embodiment is attached so as to be in contact with the surface of the living body 120 and makes the light 111 enter. The light 111 propagates through the living body 120 and is absorbed by a substance capable of estimating the blood glucose level in the blood vessel 130 to generate a photoacoustic wave signal 131. The non-invasive blood glucose measuring device 100 detects the photoacoustic wave signal 131 generated from a substance capable of estimating the blood glucose level in the blood vessel 130, and estimates a feature amount (hereinafter referred to as an estimated blood glucose level 291).

  FIG. 2 is a diagram showing a block configuration of the noninvasive blood glucose measurement device 100 according to Embodiment 1 of the present invention. In FIG. 2, 100 is a non-invasive blood glucose measurement device, 210 is a light source, 220 is a biological information sensor, 230 is an amplification means, 240 is an A / D conversion means, 250 is a storage means, 260 is a feature quantity estimation means, and 270 is an average. 280 is a signal selection means, 290 is a blood glucose estimation means, 300 is a control means, 310 is a measurement period counter, 313 is a power-off register, and 314 is a power-on register.

  The light source 210 includes at least one light source and emits light 111 having a wavelength that is absorbed by a substance capable of estimating a blood glucose level. The control unit 300 controls the lighting timing 301 corresponding to the number of repetitions of the light source 210, and further supplies the activation signal 302 to the amplification unit 230 and the A / D conversion unit 240, and the amplification unit 230, the A / D conversion unit 240, and the feature amount. An end signal 303 is output to the estimation unit 260 and a signal selection timing 311 and a signal selection reset timing 312 are output to the feature amount estimation unit 260 to control the operation of each unit.

  The biological information sensor 220 converts the photoacoustic wave signal 131 into a piezoelectric signal A221, a piezoelectric signal B222, and a piezoelectric signal C223. In the first embodiment, the channels detected by the biological information sensor 220 are three channels arranged in the order of channel A, channel B, and channel C.

  The amplification unit 230 amplifies the piezoelectric signal A221, the piezoelectric signal B222, and the piezoelectric signal C223 based on the activation signal 302 from the control unit 300, and generates an amplification signal A231, an amplification signal B232, and an amplification signal C233.

  The A / D conversion means 240 converts the amplified signal A231, amplified signal B232, and amplified signal C233 into sampling data A241, sampling data B242, and sampling data C243, respectively, based on the activation signal 302 from the control means 300.

  The storage unit 250 is an area for recording the sampling data A241, the sampling data B242, and the sampling data C243, and is written by the A / D conversion unit 240 and read by the feature amount estimation unit 260.

  The feature amount estimation unit 260 includes an averaging unit 270, a signal selection unit 280, and a blood glucose estimation unit 290. Based on the end signal 303 from the control unit 300, the feature amount estimation unit 260 reads the storage data A251, the storage data B252, and the storage data C253.

  The averaging means 270 performs an averaging process on each of the read storage data A251, storage data B252, and storage data C253, and outputs an average signal A271, an average signal B272, and an average signal C273 to the signal selection means 280. To do.

  The signal selection unit 280 selects at least one channel signal from the averaged signal A271, averaged signal B272, and averaged signal C273, and selects the averaged signal 281 after selection to the blood glucose estimation unit 290 and the amplification unit 230 and A A selection signal 282 for controlling the operation of a specific channel in the / D conversion unit 240 is output to the amplification unit 230 and the A / D conversion unit 240. In the first embodiment, the number of channels selected by the signal selection means 280 is 1.

  The blood glucose estimation means 290 calculates an estimated blood glucose level 291 using the average signal after selection 281 and outputs it to the outside.

  FIG. 3 is a timing chart of typical signals until the estimated blood sugar level 291 is output by the noninvasive blood sugar measuring device 100 according to the first embodiment of the present invention. 3, (a) is an activation signal 302, (b) is a signal selection timing 311, (c) is an estimated blood sugar level output timing, (d) is a signal selection reset timing, (e) is a selection signal 282, (f ) Is the operation of channel A amplification means and A / D conversion means, (g) is the operation of channel B amplification means and A / D conversion means, and (h) is the operation of channel C amplification means and A / D conversion means. The operation is schematically shown.

  The selection signal 282 in FIG. 3E is a signal that changes in the range from 0 to 7, and is a signal that indicates which of the channels A, B, and C is to be operated. When the selection signal 282 and the operation of each channel are shown in the form of (selection signal 282, operation of channel A, operation of channel B, operation of channel C), (0, OFF, OFF, OFF), (1, OFF, OFF, ON), (2, OFF, ON, OFF), (3, OFF, ON, ON), (4, ON, OFF, OFF), (5, ON, OFF, ON), (6, ON, ON, OFF), (7, ON, ON, ON).

  Hereinafter, the operation when the blood glucose level is estimated by the noninvasive blood glucose measurement device 100 according to the first embodiment will be described with reference to FIGS. 1, 2, and 3.

  In the first embodiment, the measurement unit is 0.1 second, the number of repetitions is 50, the measurement basic cycle is 5.0 seconds, and the measurement cycle is 3 minutes. Here, 0.9 (seconds) is set in the power-off register 313 and 170 (seconds) is set in the power-on register 314 as initial values of registers that can be written from the outside. In the first embodiment, the setting values of the power-off register 313 and the power-on register 314 are set by time. However, it may be set by the number of times of the measurement unit, and it is obvious that the same setting is possible. It is.

  First, the noninvasive blood glucose measurement device 100 according to the first embodiment is mounted on the surface of a living body 120 such as a patient's arm as shown in FIG. Thereafter, when the patient activates a blood glucose level measurement start switch (not shown) provided in the non-invasive blood glucose measurement device 100, the control unit 300 outputs an activation signal 302 to the amplification unit 230 and the A / D conversion unit 240. The lighting timing 301 of the light source 210 is controlled at the timing when the amplification means 230 and the A / D conversion means 240 enter a stable operation, and the light source 210 is turned on.

  Light 111 from the light source 210 propagates through the living body 120 and is absorbed by a substance capable of estimating the blood glucose level in the blood vessel 130 to generate a photoacoustic wave signal 131.

  The biological information sensor 220 detects the photoacoustic wave signal 131, and converts the result detected in the channel A into the piezoelectric signal A221, the result detected in the channel B as the piezoelectric signal B222, and the result detected in the channel C into the piezoelectric signal C223. .

  The amplification means 230 amplifies the piezoelectric signal A221, the piezoelectric signal B222, and the piezoelectric signal C223 converted by the biological information sensor 220 with a preset gain, and the amplification result of the channel A is the amplification signal A231 and the amplification result of the channel B is obtained. The amplified signal B232 and the amplified result of channel C are output to the A / D conversion means 240 as an amplified signal C233. Here, the activation signal 302 and the end signal 303 are input to the amplification unit 230 to enable the operation of an element such as an operational amplifier that is a component of the amplification unit 230 only at the timing when the photoacoustic wave signal 131 is generated. This is for the purpose of reducing the power consumption of the amplifying means 230. Therefore, even if these signals are not input, it is possible to perform the same operation.

  The A / D conversion unit 240 receives the activation signal 302 from the control unit 300, performs analog-to-digital conversion on the amplified signal A231, the amplified signal B232, and the amplified signal C233 output from the amplifying unit 230 at specific intervals. Sampling data A 241, sampling data B 242 in channel B, and sampling data C 243 in channel C are written into storage means 250.

  Here, the end signal 303 is input to the A / D conversion means 240 only when the photoacoustic wave signal 131 is generated, such as an A / D converter that is a component of the A / D conversion means 240. This is for enabling the operation of the element, and for the purpose of reducing the power consumption of the A / D conversion means 240. Therefore, even if this signal is not input, it is possible to perform the same operation.

  Hereinafter, a series of operations until the control unit 300 outputs the activation signal 302 and writes the sampling data A241, the sampling data B242, and the sampling data C243 in the storage unit 250 is referred to as a data acquisition period.

  The feature amount estimation unit 260 receives the end signal 303 from the control unit 300, reads the storage data A251, storage data B252, and storage data C253 recorded in the storage unit 250, and performs an averaging process in the averaging unit 270. The averaged result in channel A is output to the signal selection means 280 as the averaged signal A271, the averaged result in channel B as the averaged signal B272, and the averaged result in channel C as the averaged signal C273.

  The signal selection means 280 individually controls the operation ON / OFF of each channel in the amplification means 230 and the A / D conversion means 240 at the timing indicated by the signal selection timing 311 from the control means 300 that occurs during the averaging operation. When the selection signal 282 is output and the measurement for the number of repetitions is completed, the averaged signal after selection which is an averaged signal of the channel indicated by the selection signal 282 among the averaged signal A271, the averaged signal B272, and the averaged signal C273. 281 is output to the blood glucose estimation means 290.

  The blood glucose estimation means 290 estimates the blood glucose level based on the averaged signal 281 after selection, and outputs the estimated blood glucose level 291 to the outside at the estimated blood glucose level output timing.

  Hereinafter, with reference to FIG. 3, the detailed operation of the feature amount estimation unit 260 according to the passage of time in the non-invasive blood sugar measurement device 100 of the first embodiment will be described.

  At time 0 second, the control unit 300 outputs the first activation signal 302 to the amplification unit 230 and the A / D conversion unit 240. At this time, since the selection signal 282 indicates 7, all channels of the amplification unit 230 and the A / D conversion unit 240 operate in the data acquisition period by the first activation signal 302, and the sampling data A241 is stored in the storage unit 250. Sampling data B242 and sampling data C243 are recorded. When the first end signal 303 is output, the feature amount estimation unit 260 reads the storage data A251, storage data B252, and storage data C253 corresponding to the first activation signal 302.

  At this time, the measurement cycle counter 310 in the control means 300 starts time measurement based on the operation clock, and does not output the signal selection timing 311 because the measurement time is different from the time 0.9 seconds indicated by the power-off register 313. Since the time is different from the time 170 seconds indicated by the power-on register 314, the signal selection reset timing 312 is not output.

  At a time of 0.1 seconds, all channels of the amplification unit 230 and the A / D conversion unit 240 operate in the data acquisition period by the second activation signal 302, and when the end signal 303 is output after the data acquisition period ends. The feature amount estimation unit 260 reads the storage data A251, the storage data B252, and the storage data C253 similarly to the time 0 seconds.

  During the time from 0.2 seconds to 0.8 seconds, the same operation as the time 0 seconds is performed every 0.1 seconds as the measurement unit.

  At time 0.9 seconds, the control means 300 outputs the 10th activation signal 302 to the amplification means 230 and the A / D conversion means 240. At this time, since the selection signal 282 indicates 7, all channels of the amplification unit 230 and the A / D conversion unit 240 operate in the data acquisition period by the 10th activation signal 302, and the sampling data A 241 is stored in the storage unit 250. Sampling data B242 and sampling data C243 are recorded. When the tenth end signal 303 is output, the feature amount estimation unit 260 reads the storage data A251, storage data B252, and storage data C253 corresponding to the tenth activation signal 302.

  At this time, since the measurement time by the measurement cycle counter 310 in the control means 300 is equal to the time 0.9 seconds indicated by the power-off register 313, the signal selection timing 311 is output.

  The signal selection reset timing 312 is not output because the measurement time is different from the time 170 seconds indicated by the power-on register 314.

  When the signal selection timing 311 is output, the averaging means 270 performs an averaging process on the data for 10 times read from the storage means 250 for each of the channel A, channel B, and channel C, and selects the averaged result as a signal. Output to means 280.

  The signal selection means 280 detects the amplitude level corresponding to the fluctuation amount of the photoacoustic wave signal 131 generated in the blood vessel 130 for the averaged signal A271, averaged signal B272, and averaged signal C273, and the amplitude with the largest absolute value is detected. Select a channel with a level. In the first embodiment, assuming that channel B is selected, the selection signal 282 changes to 2. At this time, since the blood sugar level is not estimated yet, nothing is output to the average signal 281 after selection.

  At time 1.0 seconds, the control means 300 outputs the 11th activation signal 302 to the amplification means 230 and the A / D conversion means 240. At this time, since the selection signal 282 indicates 2, in the data acquisition period by the 11th activation signal 302, the channel A and the channel C of the amplification unit 230 and the A / D conversion unit 240 stop operating, Sampling data B242 is recorded in the storage means 250. When the eleventh end signal 303 is output, the feature amount estimation unit 260 reads the storage data B252 corresponding to the eleventh start signal 302.

  At this time, since the measurement time by the measurement cycle counter 310 in the control means 300 is different from the time 0.9 seconds indicated by the power-off register 313, the signal selection timing 311 is not output, and the signal selection reset timing 312 is also measured by the power-on register. Since it is different from the time 170 seconds indicated by 314, it is not output.

  From time 1.1 seconds to time 4.9 seconds, the same operation as time 1.0 seconds is performed every time measurement unit 0.1 seconds.

  At time 5.0 seconds, the estimated blood sugar level output timing (c) is output, and the averaging means 270 averages the 50 stored data B252 in the channel B output by the storage means 250 and outputs a signal as an average signal B272. Output to the selection means 280. The signal selection unit 280 outputs the averaged signal B272 as the selected averaged signal 281 to the blood glucose estimation unit 290, and the blood glucose estimation unit 290 analyzes the post-selection averaged signal 281 to estimate the blood glucose level, and the estimated blood glucose level The value 291 is output.

  During the period from time 5.1 seconds to time 169.9 seconds, the control means 300 does not output the activation signal 302 and performs only time measurement by the measurement cycle counter 310.

  At time 170 seconds, the measurement time by the measurement cycle counter 310 is different from the time 0.9 seconds indicated by the power-off register 313, so the signal selection timing 311 is not output, but the measurement time is 170 seconds indicated by the power-on register 314. Since they are equal, a signal selection reset timing 312 is output.

  When the signal selection reset timing 312 is output, the signal selection means 280 resets the selection signal 282 to 7.

  In the first embodiment, the number of channels detected by the biological information sensor 220 is 3 and the number of channels used by the blood glucose estimation means 290 is 1. However, the number of channels can be set to an arbitrary number. is there.

  Further, in the first embodiment, the selection method in the signal selection means 280 detects the amplitude level absolute value of the average signal for each channel, and the channel having the largest amplitude level absolute value in the blood vessel 130 is detected. The selection is performed with the closest channel, but the selection may be performed using time information instead of amplitude information. In this case, the time difference between the irradiation timing of the light 111 and the peak generation timing of the photoacoustic wave signal 131 generated in the blood vessel 130 is detected from the averaged signals for each channel, and the light generated in the blood vessel 130 earliest among them. The channel in which the peak of the acoustic wave signal 131 occurs may be selected as the channel closest to the blood vessel 130.

  In the first embodiment, 0.9 (seconds) is set in the power-off register 313 and 170 (seconds) is set in the power-on register 314. These set times can be freely changed from the outside. It is.

  At this time, the set time of the power-off register 313 is equal to or greater than the number of times that the signal quality of the photoacoustic wave signal 131 sufficient to select the channel installed at the position closest to the blood vessel 130 is obtained and equal to or less than the measurement basic cycle. You can do it.

  Further, the set time of the power-on register 314 is stable after the estimated blood glucose level output timing and the channel whose operation is stopped in the amplifying unit 230 and the A / D converting unit 240 is stabilized by the next measurement cycle. It may be set in consideration of the time until operation.

  Further, the following operation may be performed in the signal selection means 280 of the first embodiment.

  Channels detected by the biological information sensor 220 are used in the blood glucose estimation means 290, which is arranged in the order of channel A, channel B, channel C, channel D, channel E, channel F, channel G, channel H, and channel I. The number of channels is 1.

  Here, the operation of the amplification means 230 and the A / D conversion means 240 for all nine channels is not performed at the start of the measurement cycle, but for example, the operation is performed for five channels of channel A, channel C, channel E, channel G, and channel I. Do.

  Then, at the timing when the signal selection timing 311 is output, the averaging means 270 performs an averaging process on the data read from the storage means 250 for each of the channel A, channel C, channel E, channel G, and channel I. The result is output to the signal selection means 280.

  The signal selection means 280 interpolates the five averaged signals that have been input to create interpolation averaged signals for channel B, channel D, channel F, and channel H, and then uses the above-mentioned selection method from among all nine channels. The channel used by the blood glucose estimation means 290 is selected. For example, assume that channel D is selected at this time.

  Thereafter, until the signal selection reset timing 312 is output, the operations of the eight channels except the channel D in the amplification unit 230 and the A / D conversion unit 240 are stopped.

  When the estimated blood sugar level output timing (c) is output, the averaging means 270 outputs the interpolation signal for the measurement from the start of the measurement basic cycle to the output of the signal selection timing 311 and the signal selection timing 311 in the channel D. The averaged signal 281 after selection is created from the data obtained during the period from the start to the end of the measurement basic cycle, and the estimated blood sugar level 291 is output from the blood sugar estimating means 290.

  Further, when the average signal after selection 281 is generated, the interpolated average data is not used, but the data obtained between the output of the signal selection timing 311 and the end of the measurement basic cycle is used. An average signal 281 after selection may be created.

  In the first embodiment, the non-invasive blood glucose measurement device using the photoacoustic method has been described. However, if the signal selection method in the signal selection unit 280 is a comparison based on the magnitude of the amplitude level, other photoacoustic methods can be used. The present invention can also be applied to biological information measuring devices, or other noninvasive biological information measuring devices using Raman spectroscopy, OCT (optical coherence tomography), optical rotation angle, light absorption and transmission.

  As described above, in the noninvasive blood glucose measurement device 100 according to Embodiment 1 of the present invention, when the measurement basic cycle in which a series of operations of the measurement unit is performed X times is repeated Y times (Y is a natural number less than X). Thus, the channel to be used for estimating the blood glucose level is determined in advance by the averaging means 270 and the signal selection means 280, and the operation after the amplification means 230 of the channel not used by the feature amount estimation means 260 is stopped until X times thereafter. By doing so, a device with low power consumption can be realized.

  The noninvasive living body information measuring device concerning the present invention has a plurality of channels, and when measuring living body information after averaging a plurality of measurement results, a channel for measuring living body information in the middle of averaging It is possible to realize a low power consumption device by stopping the operation after the amplification means in the channel that is not used for measuring biological information until the averaging is completed. This is useful for improving the continuous measurement time of the instrument.

The figure which shows the system configuration | structure in Embodiment 1 of this invention. The figure which shows the block configuration of the noninvasive blood glucose measuring device 100 by Embodiment 1 of this invention. Timing chart showing the operation of the non-invasive blood glucose measurement device 100 according to the first embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Noninvasive blood glucose measuring device 111 Light 120 Living body 130 Blood vessel 131 Photoacoustic wave signal 210 Light source 220 Biological information sensor 221 Piezoelectric signal A
222 Piezoelectric signal B
223 Piezoelectric signal C
230 Amplifying means 231 Amplified signal A
232 Amplified signal B
233 Amplified signal C
240 A / D conversion means 241 Sampling data A
242 Sampling data B
243 Sampling data C
250 storage means 251 stored data A
252 Stored data B
253 Stored data C
260 feature quantity estimation means 270 averaging means 271 average signal A
272 Averaged signal B
273 Averaged signal C
280 Signal selection means 281 Average signal after selection 282 Selection signal 290 Blood glucose estimation means 291 Estimated blood sugar level 300 Control means 301 Lighting timing 302 Start signal 303 End signal 310 Measurement period counter 311 Signal selection timing 312 Signal selection reset timing 313 Power-off register 314 Power-on register

Claims (11)

At least one light source;
Control means for controlling lighting timing of the light source and activation of each means described later;
A biological information sensor of N channels (N is a natural number of 2 or more) for measuring biological information for a predetermined time;
Amplifying means for amplifying the N channel output signal obtained from the biological information sensor;
A / D conversion means for A / D converting the amplified N-channel amplified signal;
First storage means for storing the A / D converted N-channel digital data;
A series of operations until the light source is turned on and digital data is recorded in the first storage means is repeated X times (X is a natural number of 2 or more). The digital data stored in the first storage means is averaged. Averaging means to
Signal selection means for analyzing the averaged data and selecting averaged data of M channels (M is a natural number equal to or less than N) used in a feature amount estimation means described later;
In the noninvasive living body information measuring apparatus provided with the feature amount estimating means for estimating the feature amount of the biological information from the averaged data selected by the selecting means,
When the series of operations is repeated Y times (Y is a natural number less than X), a channel to be used in the feature amount estimation unit is determined in advance by the averaging unit and the signal selection unit. A noninvasive living body information measuring device which stops operation after the amplification means of a channel which is not used by the feature amount estimation means. 2. The noninvasive living body information measuring apparatus according to claim 1, wherein the signal selecting means compares the amplitude peak levels of the averaged digital data for N channels and includes an adjacent channel including a channel having the maximum amplitude peak level. A non-invasive living body information measuring device characterized by selecting an M channel. 2. The noninvasive living body information measuring apparatus according to claim 1, wherein the signal selecting means compares sampling timings at which amplitude peaks of the averaged digital data are generated for N channels, and the channel having the earliest amplitude peak generation timing. A non-invasive living body information measuring device characterized by selecting adjacent M channels including 2. The noninvasive living body information measuring apparatus according to claim 1, wherein the signal selecting means includes a writable first register, and the light source is turned on by the first register so that digital data is stored in the first storage means. The noninvasive living body information measuring device characterized in that it is possible to change the X times, which is the number of times of a series of operations until it is recorded in, from the outside. 2. The non-invasive living body information measuring apparatus according to claim 1, wherein the signal selection means includes a writable second register, and the amplification means for channels that are not used by the feature quantity estimation means by the second register. The non-invasive living body information measuring device characterized in that it is possible to change the Y times indicating the operation stop timing from the outside. At least one light source, a control means for controlling the lighting timing of the light source and activation of each means described below,
A biological information sensor of N channels (N is a natural number of 2 or more) for measuring biological information for a predetermined time;
Amplifying means for amplifying the N channel output signal obtained from the biological information sensor; and A / D converting means for A / D converting the amplified N channel amplified signal;
First storage means for storing the A / D converted N-channel digital data;
A series of operations until the light source is turned on and digital data is recorded in the first storage means is repeated X times (X is a natural number of 2 or more). The digital data stored in the first storage means is averaged. Averaging means to
Signal selection means for analyzing the averaged data and selecting averaged data of M channels (M is a natural number equal to or less than N) used in a feature amount estimation means described later;
In the noninvasive living body information measuring apparatus provided with the feature amount estimating means for estimating the feature amount of the biological information from the averaged data selected by the selecting means,
At the start of the series of operations, the operation after the amplification means is performed in the Z channel (Z is a natural number less than N), and the averaging means is performed when the series of operations is repeated Y times (Y is a natural number less than X). N channel data is created by interpolating the Z channel data input in step, and the signal selection means predetermines the channel to be used in the feature quantity estimation means based on the N channel data, and thereafter X times Is a non-invasive living body information measuring apparatus characterized in that the operation after the amplifying means of the channel not used by the feature quantity estimating means is stopped. 7. The noninvasive living body information measuring apparatus according to claim 6, wherein the signal selecting means compares the amplitude peak levels of the averaged digital data for N channels and includes an adjacent channel including a channel having the maximum amplitude peak level. A non-invasive living body information measuring device characterized by selecting an M channel. The noninvasive living body information measuring device according to claim 6,
The signal selection unit compares N sampling timings at which the amplitude peaks of the averaged digital data are generated for N channels, and selects adjacent M channels including a channel having the earliest amplitude peak generation timing. A non-invasive living body information measuring device. The noninvasive living body information measuring device according to claim 6,
The signal selection unit includes a third writable register, and the X number of times of a series of operations until the light source is turned on by the third register and digital data is recorded in the first storage unit. The noninvasive living body information measuring device characterized by being able to change from the outside. 7. The noninvasive living body information measuring apparatus according to claim 6, wherein the signal selection means includes a writable fourth register, and the amplification means for channels not used by the feature amount estimation means by the fourth register. The non-invasive living body information measuring device characterized in that it is possible to change the Y times indicating the operation stop timing from the outside. The noninvasive living body information measuring device according to claim 6,
The signal selection means includes a fifth writable register, and the Z register indicates a channel for performing the operation after the amplification means at the start of the series of operations among all N channels by the fifth register. A noninvasive living body information measuring device characterized in that it can be changed from the above.

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